If I may ask a question:
I watched the practice, and loved the flow of the attacks, but the defender movement seemed disappointing to me. Looking at the video the defender rarely moves out of the line of attack, and almost never moves forward. I don't see any Irimi or Tenkan, not to speak of other tai-Sabaki.

I only glanced over the explanation, perhaps this type of movement backwards is an intentional limitation on the practice, if so, please explain the reasons for it.

Thanks for your clarifications.
Amir

Hi Amir,

This is also in the explanation... You are right, it is one of the limitations we set up for the drills - limiting the amount of movement one can do as "defender." The point of limiting the movement - either not moving and/or only opening certain angles to which one can move, etc. - is to increase the stress and tension of the ballistic attack. The point of increasing the stress and tension of the ballistic attack is to further cultivate one's mental and technical composure, particularly regarding metsuke and Angle of Deflection (i.e. blocking, parrying, checking, etc.) - which, as you say earlier, can often break down under such pressure.

The drills are trying to cultivate greater skills under a higher scenario of duress. You can have folks punching faster, harder, etc., to do this, but once you've figured out how to move reasonably well not everyone in the dojo is going to stress your metsuke and/or your Angle of Deflection, etc. So we opt to make it harder on the "defender" by restricting him/her from relying on their body movement to relieve pressure. Under this perspective, for example, the drills are attempting to duplicate those times when your opponent is so skilled it feels like you have no Angle of Deviation because he/she is so well versed in closing off such things. However, the drills are very much aimed at telling us something about the state and/or quality of our body/mind.

Later drills, when greater and more subtle Angles of Deviations are permitted, seek to capitalize upon the higher cultivated skills of metsuke and Angle of Deviation, etc. In these drills, the restrictions limiting the attacker to only ballistic strikes are also lifted.

If you got a chance, I would recommend reading the explanation, it goes into some detail on how to perform these drills, what is being done in these drills, etc.

Hope that makes sense, if not, please feel free to ask more questions/make more comments.